ABC's of DNA: Practical Genetic Testing
T en years ago few doctors thought that they would one day be using the information from the human genome project and apply that to patient care. The first draft of the human genome was published in April 2001. Amazingly, there are now lab tests that allow doctor and patient to examine one's DNA in a constructive way.
In this brave new world we must be very careful about genetic testing. What information is useful for you to know? What do we do with the information once we have it? What if the government and/or insurance companies get hold of your laboratory data?
These are the central questions that Great Smokies Diagnostic Labs (GSDL) has been dealing with for several years, since the launch of “Genovations, Predictive Genomics for Personalized Medicine.” Let me answer the scariest question first, namely confidentiality. Genovations has been set up so that no one can have access to the results, except for your doctor.
Structure of the “Blueprint”
Before answering the other questions, we need to understand the ABC's of DNA. DNA stands for deoxyribonucleic acid. It is made up of a sugar and four chemicals called “nucleotides,” namely: Cytosine (C), Guanine (G), Adenine (A), and Thymine (T). Under normal conditions, C and G always pair with each other, and A and T always bind with each other. DNA is the blueprint of life, and it is made up of an alphabet of these four letters. When it is all put together, DNA takes the shape of a double helix, like a ladder that has been twisted around its vertical axis. It can be found on chromosomes inside the nucleus of every cell in our body.
“Imagine that the genome is a book. There are 23 chapters, called ‘Chromosomes.'
Each chapter contains several thousand stories, called ‘Genes.'
Each word is written in letters (C, G, A, and T) called ‘Bases' or ‘nucleotides.'
There are 1 billion words in this book.” — from Matt Ridley. Genome: an Autobiography of a Species in 23 Chapters.
So genes are made up of a series of bases, namely C-G and A-T. An average gene is about 3,000 nucleotides long (3,000 sets of C-G and A-T). One gene controls the expression of one characteristic, such as eye color, skin color, height, and intelligence. There are 30,000 to 40,000 genes in the human genome. At this point in time, we know the function of just about half of them.
The human body is composed of approximately 100 trillion cells. If you stretched out the DNA in one cell, it would be about six feet long. If you stretched out and connected all the DNA in one human being, it would reach to the sun and back a thousand times.
One gene codes for one protein, but first DNA must code for RNA. Then RNA codes for protein. DNA, a 4-letter alphabet, uses amino acids, a 20-letter alphabet, to create the entire human body. On one level the human being, or any creature, is a miracle of creation. Within that miracle is incredible simplicity. We have two primary alphabets, one with 4 letters and one with 20 letters, and out of that, everything we are is created.
Long ago, genetic testing meant, “trying to discover if someone has a major inherited disease such as Tay-Sachs or Phenylketonuria.” The purpose of Genovations is quite different and very sophisticated. The key to this testing is in diagnosing SNPs (pronounced “snips”). A SNP is a single nucleotide polymorphism, a slight variation in normal genetic coding. Remember that normal DNA structure involves the pairing of C with G and A with T. When there is deviation from this pairing, we have a SNP.
What Genovations Really Analyzes
Enormous amounts of research are going on to identify SNPs. Genovations tests for SNPs, but with a very clear focus in mind:
- SNPs are tested for that are associated with specific biochemical imbalances that can cause illness.
- The SNP must be “prevalent,” or very common in the population.
- The SNP must provide useful, clinical information that guides us in modifying our diet, lifestyle, and medication usage. This is the key. Genovations is not interested in testing for esoteric genetic variations that are either very rare, or for which there is no treatment.
Let's make this more relevant and down-to-earth. There are four different Genovation panels, including cardiovascular disease, osteoporosis, detoxification problems, and certain immunological and inflammatory defects.
It is important to understand that having a SNP that predisposes you to heart disease does not mean that you will develop heart disease. Your genes are your “genotype,” what you are born with. Your “phenotype” is the expression of a particular gene. For example, you may have a gene that predisposes to heart disease, but because of a healthy life style, exercise, healthy diet, and appropriate nu- tritional supplementation, that “cardiac gene” will not get expressed at all. Your phenotype will be different from your genotype.
The SNPs tested for by Genovations lead to health problems ONLY when influenced by external factors, such as diet or environmental toxicity. That is the importance of the testing. You can discover your own unique genetic weaknesses and then correct them so that you do not develop a particular illness. The key word here is “modifiable.” The only SNPs tested for are those whose expression is modifiable.
Some people want to know their genetic profile and others don't. By having this testing done, it is like knowing the cards that you have been dealt by nature. Once you know the cards you are holding, you can develop a strategy that minimizes the expression of a particular SNP. With information, you have more options at your disposal for how you will handle your life. On the other hand, I make no judgments about a person who does not want to know his or her genetic predisposition to illness.
Who Can Benefit?
1. Challenging/Refractory Cases Patients with chronic illnesses that have responded poorly to prior treatments can gain a new kind of insight, which leads to targeted treatments. Illnesses like chronic fatigue syndrome, fibromyalgia, and irritable bowel syndrome are caused by a breakdown in normal body metabolism. The chemistry of chronic illness is very complex and is caused by the interaction of genetic predisposition with external factors such as viruses and heavy metal toxicity.
To be more specific, problems in detoxification often underlie chronic illness. Genovations tests for the genes that code for the enzymes involved in detoxification, such as glutathione's enzyme system and cytochrome p-450's enzyme system.
2. Familial Association Testing
If you have a family history of heart disease, osteoporosis, or inflammatory disorders, you may go through life wondering if you are going to come down with the same illness as your mother or father. Genovations will give you a look at your genetic predisposition to these illnesses. You may discover that you do not have any risk at all for an illness you have worried about for years. Or you may discover that you do have the SNP that predisposes to a particular illness, and you will then be guided about how to modify the expression of that gene. A disease can be averted if you have identified a SNP years before the disease has a chance to develop.
3. Predictive Genomic Testing
A third reason for having Genomic Testing is to find out the hand that nature has dealt you, so that you can be pro-active, remaining strong and fit for life. Let me be more specific. Genovations can tell you if you are less likely to respond well to a particular drug or nutrient. It can tell you that you are more susceptible to environmental toxins that are most people.
We tend to believe that, if we have high cholesterol, we are at risk for heart disease. What is equally valuable is to discover if your cholesterol levels are more sensitive to a fatty diet than other people. Genovations can tell you that. You can discover if your blood is more likely to clot quickly during extended periods of inactivity compared to the average person. If you knew this, you might want to go for a 5-minute walk once an hour…or even a oneminute walk. You can discover if your blood pressure is highly influenced by salt intake or not. In other words, it is not true that salt is bad for everyone with high blood pressure.
What we are evaluating is whether or not a particular metabolic pathway of yours has a genetic weakness. If so, we want to provide support to that metabolic pathway.
Four Genomic Test Categories The metabolic pathways that Genomic Testing looks at fall into four categories:
1. Cardiovascular Disease
2. Osteoporosis/Bone Metabolism,
3. Immune Regulation (including predisposition to allergy and asthma) and lastly,
4. Detoxification/Oxidative Stress (which helps us understand cancer risk and susceptibility to exposure to toxins).
Please understand that your DNA, your blueprint for life, is not what determines your state of health and the illnesses you have. It is the interaction of our DNA with our environment (including psycho-social stressors or facilitators), the combination of Nature and Nurture, that produces the final product, namely — the current YOU.
Dennis Gersten, M.D. practices nutritional medicine and psychiatry out of his Encinitas office and can be reached at 760-633-3063. Please feel free to sign up for Dr. G's Health Digest newsletter at www.aminoacidpower.com and access 1,000 on-line pages about holistic health, amino acids and nutritional therapy.
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I struggle with uncontrolled spending. I feel as if I let all my money flow out—although I have plenty .owing in. The shopping binges seem to be as addictive for me as alcoholic binges are for alcoholics. Often I give away or throw away the things I buy. Other than compulsive, addictive shopping, I'm a health-conscious, happy person. I eat semi-vegetarian, organic foods, study Ernest Holmes's writings, a Course in Miracles, and other metaphysical literature and also do yoga. I exercise by running and walking. Is there an affirmation that can help me?
K.K., Los Angeles
My feeling is that you're emulating a family spending pattern. Did either of your parents have a problem handling money? With all the good things you do for yourself, I still sense a feeling of not-deserving or a need to punish a parent through this behavior. Why do you have to make yourself feel bad? This is an old pattern to let go of now. Work with the following affirmation for a month. Just love yourself, no matter what you may or may not do. We all deserve to be at peace.
Affirm: I DESERVE TO FEEL GOOD ABOUT MYSELF AT ALL TIMES AND IN ALL WAYS.
Do you have any secrets for healing bunions? I've suffered from them for years and don't know what to do.
Physically, bunions are toxins that settle in the feet. A good nutritional cleansing program can help your feet feel more comfortable. Metaphysically, bunions represent a fear of the future. Remember, feet represent understanding and trust in Life. So with bunions, there's fear of moving forward, and insecurity about being where you are. Also, there's the feeling that too many demands are being made on you.
It's time to stand on your own two feet mentally. What is it you want to do or be? Learn to become more selfish and to think of yourself more. You've done more than enough for others. Your feet are telling you that it's your time now. So love your feet! Massage them daily with love. Move forward in life, loving who you are, enjoying yourself, and thinking thoughts that make you feel good.
Affirm: I LOVE MY LIFE. I DO WHAT MAKES ME HAPPY, AND I MOVE FORWARD IN JOY.
You've never mentioned anything about your views on the subject of a married woman having a sexual relationship (four years now) with a divorced man. What is your view on extramarital affairs?
S.K., Asheville , NC
Other people's extramarital affairs are none of my business. We're all under the law of our own consciousness. When we settle for less, we get less. The majority of the time in these cases, the relationship doesn't progress very far. Promises may be made but are seldom fulfilled. The questions to ask yourself are: “Is this what I really deserve?” “Is this what I really want, and why?” “Do I enjoy living a secret life?”
No one can tell you what to do or make a decision for you, because they're not you. They don't think in your mind. Only you can give yourself pain or happiness. I would affirm: I AM LIVING A BEAUTIFUL AND FULFILLING LIFE. I AM HAPPY AND AT PEACE. Then see how the Universe fulfills these affirmations for you.
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